An object of a communication system is to transmit a large amount of data at a low error rate. To achieve this, the communication system should have a high system capacity. In recent years, a femtocell technology for decreasing a cell radius to decrease an interval between a user and a Radio Access Unit (RAU) and thus improve performance, a Coordinated MultiPoint (CoMP) technology for improving the performance of a cell boundary user equipment through coordinated transmission of adjacent base stations, a Virtual Cell Network (VCN) technology and the like have been proposed.
A VCN represents a network topology of adaptively forming virtual cells and providing a service so as to maximize a frequency resource use efficiency in a multiple-cell environment in which user/traffic/interference characteristics are different from one another. Distributed base stations or distributed small base stations, which belong to the virtual cells, share information in real time. Based on the shared information, the DBSs can control interference using a transmission technique such as coordinated beamforming and the like. This VCN environment improves performance through a spatial reuse of wireless resources. However, frequent handover takes place between the virtual cells. Because a boundary region between the virtual cells is a boundary between small base stations having small coverage, a handover region is narrow and there is a possibility in which handover is carried out at a low reception signal level. Accordingly, there is a need to efficiently improve a mobility problem between virtual cells formed by a plurality of distributed small base stations such as the VCN.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present disclosure.